Folding stairway



NOV. 5, 1940. F JACHlM 2,220,155

FOLDING STAIRWAY Filed Aug. 8, 1958 2 Sheets-Sheet 1 .CU J /Lf l Pme BYATTORNEY.

Nov. 5, 1940. F CHN 2,220,155

FOLDING STAIRWAY Filed Aug. 8. 1938 2 'Sheets-Sheet 2 lll ATTORNEY.

Patented Nov. 5, 1940 UNITED STATES PATENT OFFICE 4 Claims.

This invention `relates to an improved folding stairway which isexceptionally rugged and sturdy although/ exceeding light in weight. Theimproved folding stairway of this invention is e especially adapted foremployment in conjunction with a tank having a floating roof.

One of the principal objects of advantage and importance of the improvedfolding stairway of this invention resides in the provision of means lowhereby one end of the device may be raised or lowered at will. l

Another and still further important object of advantage resides in theprovision of means for maintaining the treads horizontal regardless ofl5 the angle at which the stairway is positioned.

Still another and further object of advantage resides in the provisionof means for maintaining a hand rail between the anchor post and the endof the stairway.

An additional object of importance of the improved folding stairway ofthis invention resides in the provision of means for forming a runwaywhen the stairway is in a horizontal position.

Additional objects of advantage and importance will become apparent asthe following detailed description progresses, reference being had tothe accompanying drawings, wherein Fig. 1 is a side elevational view `ofa folding stairway which embodies the invention.

Fig. 2 is a side elevational view of the stairway elevated to ahorizontal position.

Fig. 3 is a horizontal section taken on line 3-3 of Fig. 2, looking inthe direction indicated by the arrows.

Fig. 4 is a vertical section taken on line 4-4 of Fig. 2. l

Fig. 5 is a vertical section taken on line 5-5 of Fig. 1.

As shown in the drawings:

The reference numeral I0 indicates generally the anchor posts which inthe preferred embodiment of the invention are constructed of angle iron.However, it will be apparent that any other suitable anchorage may beemployed.

Hingedly secured to each anchor post III is a supporting member I2 whichis preferably constructed of angle iron. A tierod I4 may be secured tothe supporting member I2. Where the tierod I4 is used the supportingmember I2 may be constructed of light weight material without danger ofits sagging or becoming otherwise distorted.

Positioned closely adjacent the free end of each supporting member I2 isa wheel I6. 'I'he wheel I8 provides a means for allowing the end ofthestairway to move over a surface as the structure is raised or lowered.

Hingedly secured to each anchor post I0 is a tread leveling member I9.The tread l'veling members I8 are secured at one end to the anchor- 5age and extend substantially parallel to the supporting member I2,

Hingedly secured tothe outwardly projecting end of each tread levelingmember I8 is a tread supporting membery 20. The tread supporting 10members 20 are preferably constructed of angle iron as is clearly shownin the drawings. It will bev apparent however that any suitable materialmay be employed for a tread supporting member. The tread supportingmembers 20 and the supl5 porting members -I2 form front and rear treadsupporting units, respectively. Tread supporting members are positionedon each side of the improved stairway of this invention. Each treadsupporting member 20 is positioned above a 'sup- 20` porting member I2and is at all times parallel thereto.

Positioned between each pair of parallel supporting members I2 and 2U isa plurality of treads 22. Each tread is preferably constructed 25 ofsheet metal and has at each end thereof an upwardly and a downwardlyturned lug 24 and 26, respectively. Each of the lugs 24 and 26 areapertured to receive a bolt.

In the preferred embodiment of the invention 30 the upwardly projectinglug 24 is adapted to be secured to the tread supporting member 20 andthus support the forward portion of the tread. The downwardly projectinglug 26' is adapted to be secured to the supporting member l2 and 35 thussupport the rear portion of the tread.

Projecting upwardly from tread supporting member 20 is a plurality ofstandards 28 which are adapted to support a hand rail 30. The portion ofthe hand rail which is secured to the 40 anchor post IU is preferablyconstructed of tubing 32. A portion of the hand rail is adapted to betelescoped vwithin the tubing 32. This construction provides a hand railextending from the anchor post to the end of the stairway re- 45 I vItwill be apparent from the foregoing that 55 the improved foldingstairway ofthis invention may be used as a fire escape or forpractically any purpose for whichma folding stairway is adapted.

5 Moreover, when the stairway is raised to the horizontal position eachtread comes into edge to edge abutment with the next tread thus forminga practically smooth runway.

It will be apparent to those skilled in the art l to which the inventionappertains that numerous changes and alterations may be made with- 4out-departing from the spirit or scope of the invention. Accordingly, it isunderstood that the patent granted hereon is'to be limited only as 15 isnecessitated by the prior art and the terminology of the claims whengiven the range of' equivalents to which they may be entitled. i I claimas my invention:

1. In a folding stairway, a pair of vertical 9" anchor posts in spacedparallel relation, a tread leveling link member pivotally secured toleach anchor post, an upper tread supporting member pivotally secured tothe outer end of each link,

supporting member pivotally secured to each .of

said anchor members, a plurality of treads pivotally secured adjacentthe rear edge thereof to said tread supporting members, a pair of uppertread supporting members, said treads being pivotally secured adjacentthe front edges thereof to said upper tread supporting members, and amovable pivot to which the secured end of the upper tread supportingmembers is journaled, said movable pivot comprising a leveling linkextending from the journaled end of each upper tread supporting memberand having the other end thereof pivotally secured to an'anchor member.

3. In a stairway, an anchor member, a pair of lower tread supportingmembers hingedly joined to said anchor membensaid anchor member pro- 10viding a fixed pivot upon which the tread supporting members may move, apair of upper tread supporting members, one end of said tread`supporting members being joined to a movable pivot, said movable'pivotcomprising a pair of tread 15 leveling link members pivotally secured tosaid anchor member and said tread supporting mem- \`bers, said rtreadleveling link members being adapted to move into engagement with thelower tread supporting members when the stairway is raised to ahorizontal position, and a. plurality of treads pivotally secured tosaid upper and said lower tread supporting members.v

4. In a stairway, an anchor, a'pair of tread supporting memberspivotally secured to said anchor, a plurality of treads pivotallysecured adjacent the rear edges thereof to said tread supportingmembers, a pair of upper tread supporting members pivotally secured tosaid treads closely adjacent the forward edge thereof, the upper end ofeach upper tread supporting member being journaled to a movable pivot,said movable pivot comprising a tread. leveling link pivotally securedto said anchor, said link providing an angularly disposed bracebarring-the upward movement of the stairway from a horizontal position.

FRANK JACHIM.

